Mostly whitespace changes, with max-line-length set to 120 and double-quotes used, adopting black settings. Related to https://github.com/capnproto/pycapnp/issues/128
Mostly whitespace changes, with max-line-length set to 120 and double-quotes used, adopting black settings. Related to https://github.com/capnproto/pycapnp/issues/128